Frame material hierarchy

[tintin40]

I must say carbon is rubbish for mtb's

 

[Midlife]

My 7 year old could put frames better together than the Titanium frames made by Speedwell in the 70's LOL

Shaun

 

[tintin40]

Jeez, whatever next - who's got the best religion?

Agree. All have their pro's & con's. Atheism looks good to me.

And as for frame materials depends on who you ask

 

[FairfaxPat]

I have been riding a carbon framed MTB for 3 years now, and I love it! I have owned 20-30 other bikes of steel and aluminum over the years and most were good, also.

 

[Chopper the ex Copper]

Depends what up mean by best.

My personal favourite is steel. It has better ductility than both Ti an Al, so less is needed in the first place.

Various grades suit different purposes, so I'd hesitate to suggest 853 is "best" when it's know where near as hard as cheapo Mangalloy, which is steel with 13ish% magnesium.

My favourite general purpose steel is 4130 chromo which is reasonably priced and a good performer, but other steels are superior for particular specialist applications.

Aluminium is a highly inappropriate material for a quality frame. It's ductile limit is a fraction of steels which gives it a limited effective life compared to steel.

Composites are great, but are too fragile for MTB use, and they can suffer aged related issues.

Ti. Strong, light, but quite flexible compared to steel making it an inferior choice for load bearing applications. Bit works just fine but steel actually performs better than Ti in frames, skewers etc. by jolly can it look nice though.

Of course, I'm ignoring economics, market forces, fashion etc and just concentrating on the performance characteristics of each material.

 

[FairfaxPat]

Gotta disagree with you, Chopper, about carbon for MTB's being too fragile. I have ridden the heck out of my carbon MTB for 3 years-about 4000 miles in the dirt per year, with no problems, and it isn't smooth, easy riding around here, either.

 

[hamster]

Ti. Strong, light, but quite flexible compared to steel making it an inferior choice for load bearing applications. Bit works just fine but steel actually performs better than Ti in frames, skewers etc.

Hence all the steel jet fighters. :roll:

Ti is lighter than steel for a given strength, but is a horror to process, weld and machine. SO most Ti bikes are relatively simple in tubing design compared to steel. I agree with you for the end result, but it's more about the processability of Ti than the inherent strength properties.

Its corrosion resistance is a decided advantage, although some of the new super steels for framebuilding are now in the same territory. But apparently 853 and 953 are now ghastly to machine.

 

[FMJ]

bamboo

 

[Chopper the ex Copper]

Gotta disagree with you, Chopper, about carbon for MTB's being too fragile. I have ridden the heck out of my carbon MTB for 3 years-about 4000 miles in the dirt per year, with no problems, and it isn't smooth, easy riding around here, either.

Take a carbon frame, hit it with a rock. Now take a similarly dimensioned steel frame and do the same.

I normal riding it'll be fine, but because carbon can't be strong in all planes at once it is simply more vulnerable to impact damage than any metallic frame, simple fact of life.

The Mig 25 is indeed all steel, stainless in that case, because it was the only material that could cope with the thermal loading and be roduction friendly in the late 60's. The SR71 was Ti but was pushing the boundaries of cobstruction technology for the time. Most airframes are mainly alloy, but have a finite life in hours as a consequence. The loading per KG of metal that a bicycle frame has to endure is many, many times that of an aircraft do its a bit of a ridiculous comparison. Conversely, a bicycle dies not have to get tens of tonnes of fuel airborne so does not need as light an airframe as possible as the primary consideration.

 

[greenstiles]

My Columbus Foco frame would not survive a rock ! it was too fragile for me. But any good steel frame at around 4-4 1/2lb will bo me...the Foco was 3.7, fine for Ti but not steel. Out of the 50 ish bikes i've owned plus others ridden ie demo in our shops........I still prefer steel hardtails.

Alu for full sus. Carbon, of the ones i've tried not impressed, but perhaps i didn't try a good one.